A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated. The optical microcavity consists of a half wavelength–thick waveguide for vertical confinement and a two-dimensional photonic crystal mirror for lateral localization. A defect in the photonic crystal is introduced to trap photons inside a volume of 2.5 cubic half-wavelengths, approximately 0.03 cubic micrometers. The laser is fabricated in the indium gallium arsenic phosphide material system, and optical gain is provided by strained quantum wells designed for a peak emission wavelength of 1.55 micrometers at room temperature. Pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.

https://science.sciencemag.org/content/sci/284/5421/1819.full.pdf

Two-Dimensional Photonic Band-Gap Defect Mode Laser

Organic semiconductor lasers.

An imaging system for a vehicle includes an imaging device having a field of view exteriorly and forward of the vehicle in its direction of travel, and an image processor operable to process the captured images in accordance with an algorithm. The algorithm comprises a sign recognition routine and a character recognition routine. The image processor processes the image data captured by the imaging device to detect signs in the field of view of the imaging device and applies the sign recognition routine to determine a sign type of the detected sign. The image processor is operable to apply the character recognition routine to the image data to determine information on the detected sign. The image processor applies the character recognition routine to the captured images in response to an output of the sign recognition routine being indicative of the detected sign being a sign type of interest.

Imaging system for vehicle

A rearview vision system (12) for a vehicle includes at least one image capture device (16) directed rearwardly with respect to the direction of travel of the vehicle. A display system (20) displays an image synthesized from output of the image capture device. The display system is preferably contiguous with the forward field of view of the vehicle driver at a focal length that is forward of the vehicle passenger compartment. A plurality of image capture devices (14, 16) may be provided and the display system displays a unitary image synthesized from outputs of the image capture devices which approximates a rearward-facing view from a single location, such as forward of the vehicle.

Rearview vision system for vehicle including panoramic view

A personal digital assistant (PDA) (10) stores data from physiological monitors (12) so that the data can be used in various software applications. In different embodiments the physiological monitor (12) can include data storage or have memory modules that are accepted by accessory slots (48 and 50).

Physiological monitor and associated computation, display and communication unit

A novel electro-opto-mechanical assembly is provided. The electro-opto-mechanical assembly comprising: a first wafer, the wafer having a top and bottom surface; at least one optical element disposed on one surface of the first wafer; at least one discrete opto-electronic transducer element disposed on the bottom surface of the first wafer and in optical communication with the optical element; and an optical waveguide; wherein the first wafer and the optical element form an optical relay which relays light between the discrete opto-electronic transducer and the optical waveguide and thereby forms an efficient optical coupling between the discrete opto-electronic transducer and the optical waveguide.

Opto-mechanical assembly

An optical memory system employing multiple reading/writing optical beams from solid state lasers for simultaneously reading from a writing to multiple tracks of optical media to allow reading/writing of closely spaced adjacent tracks, a number a feature are disclosed. These include using vertical writing surface emitting lasers forming an array of beam sources, using lenslets associated with array, modulating the beams, and providing various optical elements and combinations of optical elements to compensate for beam and system imperfections.

Multiple beam optical memory system with solid-state lasers

A vertical-cavity surface-emitting laser is disclosed comprising a laser cavity sandwiched between two distributed Bragg reflectors. The laser cavity comprises a pair of spacer layers (20, 40) surrounding one or more active, optically emitting quantum-well layers (30) having a bandgap in the visible which serve as the active optically emitting material of the device. The thickness of the laser cavity is m μ/2neff where m is an integer, μ is the free-space wavelength of the laser radiation and neff is the effective index of refraction of the cavity. Electrical pumping of the laser is achieved by heavily doping the bottom mirror (10) and substrate (60) to one conductivity-type and heavily doping regions of the upper mirror (50) with the opposite conductivity type to form a diode structure and applying a suitable voltage to the diode structure. Specific embodiments of the invention for generating red, green, and blue radiation are described.

Visible light surface emitting semiconductor laser

Distributed feeback mirror cavities are found capable of sufficient reflectance-loss characteristics to permit lasing in two or a single quantum well structure in which lasing is in the thin (quantum) dimension. Such lasers sometimes known as "quantum well surface emitting lasers" are of sufficiently low threshold value as to permit use in integrated circuits of high integration density - e.g. at 1 micron design rules. Anticipated uses, now made possible, include optical circuitry for computer chip interconnect as well as optoelectric integrated circuits for many purposes including computing itself.

Quantum well vertical cavity laser

A three-dimensional optical interconnection is disclosed having a stack of vertically aligned optoelectronic integrated (OEIC) modules. Each OEIC module includes an array of vertical cavity surface emitting lasers (VCSEL), receivers and electronic logic which are monolithically integrated on a single semiconductor substrate. Communication between the OEIC modules is effectuated by the free space propagation of laser radiation from the VCSELs to corresponding receivers on an adjacent OEIC module. Transistors, such as heterojunction bipolar transistors, may be used to drive the VCSELS.

Jack L. Jewell

Papers

Opto-mechanical assembly

Multiple beam optical memory system with solid-state lasers

Visible light surface emitting semiconductor laser

Quantum well vertical cavity laser

Vertical-cavity surface emitting laser optical interconnect technology